MTS Series 793 User Manual
Page 75
How to Manually Tune the Control Loop
MTS Series 793 Tuning and Calibration
Tuning Procedures
75
Unstable sounds
For actual testing, if your system goes unstable it will sound unstable—that
is, it will emit an annoying high-pitched sound that is quite different from
the usual tuning sound (“ka-chunk, ka-chunk”). If your system begins to go
unstable, quickly readjust the control that caused the instability to return the
control to its previous setting.
Rule-of-thumb
Adjust the P Gain and D Gain controls as high as possible without going
unstable.
9. Adjust the I Gain tuning control.
Set up a peak/valley meter to monitor the peaks and valleys of the sensor
signal. The peaks and valleys should be balanced. Before adjusting reset (I
Gain), be sure the feedback signal is repeatable (that is, the same peaks and
valleys are achieved).
For example, assume the test command is centered on zero and the meter
displays +3 mm and -5 mm. You want to adjust the reset (I Gain) control to
achieve ±4 mm.
If the command is not centered on zero, monitor the difference between
peaks and valleys of the sensor feedback to the upper and lower levels of the
test command. Any difference should be the same.
Note
You can also use the Scope (optional for FlexTest SE) or an external
oscilloscope to adjust I Gain by monitoring the Error signal. For more
information, see
“How to Use Error to Tune I Gain”
10. Save your tuning settings.
Standalone FlexTest SE Controllers: Setup > Open/Save Parameters >
<<Save>>
Automated Controllers: On the Station Manger File menu, select Save
Parameters As.
You can either select an existing parameter set or enter the name of a new
parameter set to save.
About saving elements
of a parameter set
It is important that you save your parameter set as you complete the various
parts that make up a parameter set. Throughout this manual you will be
performing discrete procedures while building a single parameter set.
•
If you have already established your default parameter set for the
current station and you are creating a new parameter set for a specific
test, save the parameters with a different name.
•
Different tests and/or specimens may require different parameter sets.